Locomotive-valve gear



April l0, 1928. 1,665,966

J. KUPKA LOCOMOTIVE VALVE GEAR Filed @ne 18, 1925 U .-177L f 2 *W5 1 12 2f 11 3 qu 6 en YZ g i 2 l@ O l u 1g l lb E Patented Apr. 10, 1928.

JOHANN KUPKA, 0F VIENNA, AUSTRIA.

LOCOMOTIVE-VALVE GEAR.

Application led .Tune 18, 1925, Serial No. 38,063, and in Great Britain February 24, 1925.

This invention relates to improvements in valve gear, more particularly locomotive valve gear, of the kind comprising poppet or mushroom valves actuated by cams on a rotary or oscillatory shaft. In valve gear of this kind the direction in which the thrust cam being thus communicated to the spindle substantially in alignment with its longitudinal axis whilst the cam has a sliding movement along a part of one edge of the lever to swing the latter on its pivotal support which is arranged parallel to the axis of rotation of the cam.

This invention provides an improved method of supporting such interposed levers so that they can be more conveniently and efficiently lubricated and also permits the levers to be conveniently removed and replaced in the cam chamber for example for renewal or repair. This improved construction is especially applicable and advantageous in cases in which the cam spindle is arranged in a chamber which can be opened at its ends, and is separate from the steam and exhaust spaces.

In the accompanying drawings:

-Figure 1 shows longitudinal vertical sections on different planes'through the upper v part of a steam engine cylinder and through a valve chest mounted thereon provided with valves operated by cams through interposed levers arranged in accordance with this invention.

Figure2 is a sectionalI plan view thereof.

Figure 3 shows a transverse section through the valve chest on the centre line of the cam spindle.

Figure 4 is a perspective view of a lever supporting bar and an end plate in which this bar is mounted.

Referring to the drawings, 1, 1, aresteam valves of a locomtive and 2, 2, are exhaust valves each of said valves being of the semibalanced or dierential type held against their respective seats by pressure 0i steam 1n the steam vsupply conduit or in the cylinder and mounted on valve spindles 3 passing steam tight through a packing piece 4 into a cam chamber 5. A. cam shaft 6 passing through this chamber carries cams 7 which act upon rollers 8 carried on levers 9 pivotally supported at 10 so that, as the shaft 6 rotates the levers 9 are thrust by the cams against the inner ends of the spindles 3 to open the valves against the steam pressure acting thereon. In order to hold the valve stems in contact With the levers,.if the valves at any time are relieved of steam pressure tending to close them, thrust rods 11 arepressed by springs 12 against the valve stems so as to hold the latter in contact with the levers.

The chamber 5 in which the cams and cam shaft are arranged is separate from the live steam and exhaust spaces vwithin the valve box and may be open at its ends. A bar 13 is supported in the lower part of this chamber and this bar is'provided with lugs 14 carrying the pivot pins 10 on which the levers 9 are mounted. By drawing the bar 13 out of the chamber 5 the levers 9 are carried with it. In a convenient arrangement for supporting the bar the chamber 5 is provided with end plates 15 bolted to the va ve box and having bearings therein for the cam shaft 6, and sockets in which dowels 16 provided at the ends of the bar 13 can be held.

An essential feature in the construction hereinabove described is the arrangement of the lever pivots 10 at the lower ends of the levers 9. By this means the constant lubrication of the lever pivot pins can be ensured by flooding the bottom of the chamber 5 with lubricant. By enclosing the cam shaft and cams in a space to which access can be had from the sides of the valve chest, instead of through the top of the chest, the steam space 17, as well as the exhaust space 18, may be extended from end to .end ofthe chest, to serve both ends of the' cylinder, it then being necessary to provide only one inlet 19 for admitting steam to the valve chest, instead of providing a branched steam supply pipe.

By reason of the ease with which ac cess can be had to the bar 13, this means of supporting the levers 9 is especially suitable for the engines of locomotives with inslde cylinders.

I claim:

locomotives comprising a spindle carrying the valve, a chamber separate from the inlet and exhaust steam spaces of the steam chest, end plates for said cam chamber, a cam and a pivotally supported lever arranged in said chamber, said lever being interposed between ary bar carrying the pivot of said lever, said bar being longitudinally removable from said cam chamber.

3. Valve actuatin mechanism for steam locomotives comprismg a cam chamber isolated from the steam spaces in the valve chest, a valve spindle projecting into said cam chamber, a pivoted lever, a cam, a spring operating through the spindle to urge the lever towards the cam, and a bar carrying the pivot ofsaid lever, said bar being longitudinally removable from said cam chamber.

4. Valve actuating mechanisnr for steam locomotives comprising a valve spindle, a cam chamber isolated from the steam spaces of the valve chest, a .cam in said chamber, a pivoted lever interposed between one end of the spindle and the cam, a roller carried by said lever between its ends for engagement by said cam, a spring thrusting against the other end of `the spindle, and a bar longitudinallyremovable from said cam chamber and carrying the pivot of said lever.

5. Valve actuating mechanism for steam locomotives comprising a cam chambery end plates for said chamber, a lever pivoted at one of its ends and arranged in said cam chamber, a valve spindle yieldingly pressed against one side of the end of the lever revmote from the p-ivot, a cam onthe opposite side of the lever, a roller carried by said lever between its ends for engagement by the cam to move the valve spindle, and a bar carrying the pivot of said lever and supported by the end plate.

6. a steam 'eng1ne, a valve chest, a cam chamber in the said chest, a cam within the chamber, a valve spindle extending into the chamber, a lever interposed between the cam and the spindle end, platesat the ends of the chamber, a bar supported by' the plates, and a pivotal support of the lever carried by the said bar.

7. In a steam engine, a valve chest, a live steam space and an exhaust space each extending from end to end of the valve chest, a cam chamber separate from thc said steam and exhaust spaces, plates for closing the ends of said cam chamber, spindles extending into the said chamber, poppet valves carried by said spindles, a shaft extending into said cam chamber, cams ior operating the valves carried by said shaft, levers interposed between said cams and spindles, a bar supported by said endplates, and means for mounting said levers on ysaid bar.

8. ln a steam engine, a valve chest, a cam chamber within the chest, end plates for closing the ends of said cam chamber, a cam Within the chamber a valve spindle extending into the chamber, a lever interposed between the cam and the end of the spindle, a bar removably supported by said end plates Within the chamber, and a pivotal support on the said bar for the interposed lever.

9. ln a steam engine, a valve chest, a live steam space and an exhaust space, each extending from end to end of the valve chest, a cam chamber separate from the said steam and exhaust spaces, end plates for closing said cam chamber spindles extending into said chamber, poppet valves carried by said spindles, levers interposed between the cams and the ends of the spindles, a bar supported Within the chamber by said end plates, and a pivoted support on the said bar for the interposed levers.

10. Valve actuating mechanism for steam locomotives comprising a valve spindle, a

cam chamber separate from the steam spaces on the valve chest, plates at the ends of said chamber, a bar supported by said plates, a lever pivoted in said bar, said lever having its pivotal support at one end thereof and having its opposite end arranged to bear against one end of the valve spindle, a cam arranged to act on an intermediate part of the' lever. v

-THANN KUPKA. 

